Epidemiology of healthcare-associated infections and mechanisms of antimicrobial resistance of responsible pathogens in Ukraine: Results of a multicentre study (2019-2021).

Background, Healthcare-associated infections (HAIs) caused by multidrug-resistant organisms (MDROs) are severe complication acquired in healthcare settings with high impact in terms of morbidity, mortality and costs. Aim, The aims of this study were to estimate the prevalence and incidence of HAIs, and to describe phenotypic and genotypic features of antimicrobial resistance in responsible pathogens in Ukraine. Methods, Prospective multicentre surveillance conducted from January 2019 to December 2021 in 17 regional hospitals of Ukraine. Definitions of HAIs were adapted from the Centers for Disease Control and Prevention's National Healthcare Safety Network. Species identification was performed with standard microbial methods. Antibiotic susceptibility testing of bacteria was determined by Kirby-Bauer disc diffusion test according to the protocol of the European Committee on Antimicrobial Susceptibility Testing. β-lactamases genes were investigated by polymerase chain reaction. Findings, Among 37,968 patients, 6,218 (16.4%) HAIs were observed. Of all HAI cases, 14.8% were detected after hospital discharge. The most frequently reported HAI types were pneumonia (24.4%), urinary tract infections (19.8%), surgical site infections (15.3%), and bloodstream infections (11.2%). Of all HAI, 11.9% were defined as part of an outbreak. Death during hospitalization was reported in 12.6% of HAI cases. In total, 85.1% isolates from patients were found to be MDROs. The predominant pathogens for HAIs were Escherichia coli (21.3%), Enterobacter spp.(12.9%), Klebsiella pneumoniae (10.8%), Staphylococcus aureus (9.1%), Pseudomonas aeruginosa (8.1%), Enterococcus spp. (7.3%), Proteus mirabilis (6.8%), Acinetobacter baumannii (6.1%), Stenotrophomonas maltophilia (5.7%), and Serratia marcescens (5.3%). Meticillin resistance was found in 41.2% of S. aureus (MRSA) isolates, and vancomycin resistance was found in 11.8% of enterococci (VRE). Antimicrobial resistance to third-generation cephalosporins was detected in 48.4% of all Enterobacteriaceae, and was most common among K. pneumoniae (77.5%) and E. coli (46.2%). Carbapenem resistance was found in 17.3% of Enterobacteriaceae, and in 17.4% and 53.6% of Enterobacter spp. and K. pneumoniae isolates, respectively. Antimicrobial resistance to carbapenems was detected in 71.3% of all nonfermentative Gram-negative bacteria, and was most common among A. baumannii (74.7%), and P. aeruginosa (67.9%). Of the all isolates tested, 25.1% were found to be multidrug-resistant (MDR). The predominant MDROs were A. baumannii (68.7%), K.pneumoniae (58%), P.aeruginosa (54.3%) S.aureus (41.2%), E.coli (12%), E. faecium (11.8%), and S. maltophilia (11.5%). Overall, 38.5% of the MDROs had β-lactamases genes, including ESBLs (41.3%), OXA-type (29.7%), AmpC-type (25.8%), KPC-type (24.9%) and Metallo-β-lactamases (44.7%), including IMP-type (11.9%), VIM-type (23.1%) and NDM-1 (24.9%). Conclusions, This study found high prevalence of HAIs; those caused by MDROs varied widely depending on the bacterial species, antimicrobial group and geographical region of Ukraine. MDROs were one of the main causes of HAI-associated deaths.